Effect of decapitation and chronic in-vivo treatment with a gonadotrophin-releasing hormone agonist on testicular steroidogenesis in the rat fetus.

摘要: To study the effect of in-vivo gonadotrophin-releasing hormone (GnRH) treatment on testicular testosterone production during late fetal life in rat, 18.5-, or 20.5-day-old fetuses were decapitated and injected with either long-acting microcapsules containing GnRH agonist D-Trp-6-GnRH vehicle only. Two days later, maternal plasma was collected testes removed incubated for 6 h medium 100 ng LH/ml without LH. The concentrations GnRH-treated male comparable two age-related groups (5 nmol/l). After fetus D-Trp-6-GnRH, recovered plasma, showing that this peptide can cross fetal-maternal barrier. In 22.5-day-old vehicle-treated fetuses, level dropped to observed control female did not further reduce it. At both 20.5 22.5, basal in-vitro secretion by from lower than intact same litter, but LH-stimulated similar groups. Both larger reductions measured day 22.5 (-48 vs -18% secretion, -76 -40% secretion).(ABSTRACT TRUNCATED AT 250 WORDS)